The invention relates to a module holder for holding electronic modules, having two lateral parts and four connecting pieces, in which the backwall wiring includes a printed circuit board which is attached to the two rear connecting pieces in a mechanically detachable manner.
Module holders are disclosed in Siemens-Zeitschrift 46 (1972), at pages 277 to 279. In existing module holders the lateral parts are screwed to four connecting pieces at the corners. Fitted into the backwall of these module holders are male or female connectors ("spring or knife strips") of multi-pole plug connectors, whose wiring-side contact pins form the wiring field of the module holder. Such male and female connectors are also disclosed in Siemens-Zietschrift 46 (1972), at pages 279 and 280. The electrical connections in this wiring field may be produced with discrete wiring or by circuit board wiring (see for example from Siemens-Zietscrift 46 (1972), pages 286 to 288). Discrete wiring is being replaced increasingly by wiring with printed circuit boards, referred to as back panels or platters. These platters are normally attached to the connecting pieces of the module holder with screws. For maximum mechanical strength, the distances between the screws are relatively small. Also, the copper area of the printed circuit board is interrupted at the screw points. This face must be taken into consideration in the designing of the circuit board. Additionally, due to different temperatures during manufacture, transport and use, the dimensional differences between the module holder backwall and the platter may increase to over 1 mm, resulting in high mechanical stresses and possibly malfunctions in view of the small distances between screws.